In small plot gardening prior to the 1930s, the only method of tilling or breaking up the soil was to utilize a pick and shovel. In the 1930s, however, the advent of the small engine garden tiller provided a second option for accomplishing the task of small plot tilling and cultivating. Since the 1930s, the garden tiller has changed in size to accommodate the generally smaller garden plots which have evolved since that time. The only major alteration from the original garden tiller design has been movement of the tiller tines from the front of the device, or in front of the wheels of the device, to a position rearward of the wheels. While this modification of moving the tines from a front position to a rear position gained some advantages in control of the garden tiller, it sacrificed the area of safety. In positioning the rapidly rotating tiller tines proximate to the feet of the tiller operator, a substantially greater danger is presented to a user.
This modification of moving the tiller tines from the front to the rear of the tiller--behind the wheels--was in response to a major difficulty presented by front tine tiller devices. This difficulty is the lack of control over tiller movement and rate of travel of the front tine tiller by a user thereof. While operating a rotary tiller is significantly easier than hand spading of a garden plot, nevertheless, substantial effort is required in attempting to control a front tine tiller. As a result of the front positioning of the tiller tines the machine, during operation, evidences a strong tendency to move rapidly along the surface of the ground by "walking" along under the power of the rotating tines. It is, of course, preferred that the machine not move rapidly along the surface of the ground, but rather, move at a slower rate so the rotating tines have an opportunity to dig into the ground and to break up, turn, and loosen the soil of the garden plot.
A second major problem of front tine tillers is the lack of maneuverability of the device. Though the rotating tines move the device in a forward direction along the ground, no portion of the device assists in turning the rotary tiller to the right or to the left other than the force applied by the operator to the handlebars of the device. Various implements have been added to the rotary tiller to assist the user in turning the device and regulating the speed of the device as it moves along the ground.
One such device commonly observed on a rotary tiller is a drag stake mounted behind the wheels of a front tine rotary tiller. The object of the depth stake is to assist in controlling the movement of the rotary tiller by limiting the speed at which the tiller can move in a forward direction over the ground. This is accomplished by the drag stake or drag bar engaging the soil behind the rotary tiller and providing a drag on the entire machine. Also, it is intended that the drag stake be utilized to adjust the distance into the ground which the tiller cultivates. This is accomplished by raising or lowering the depth stake to provide more or less penetration into the ground. When the depth stake or drag bar is extended further into the ground a greater restraint or drag is placed upon movement of the rotary tiller and the tiller spends more time at a single location thus allowing it to dig deeper into the ground.
However, the depth stake itself provides a number of difficulties and limitations in use. When the rotary tiller is initially used on unbroken ground it is difficult to secure the depth stake in the ground to provide the desired drag or resistance. Therefore, the depth stake is of little use until the rotary tiller has cultivated sufficient ground as to bring the depth stake into a tilled area where it may be pushed down into the ground to provide the desired resistance. A second difficulty of the drag stake is that it tends to make poor contact with the ground when the tiller operates on a side-to-side incline. When the user is holding the tiller on a side-to-side incline, such as near the base of large plants or bushes where the soil has been mounded about the plant, the drag stake may inadequately engage or come free of the ground thereby failing in its function.
Most importantly, the conventional depth stake fails to provide any assistance to the user in controlling the direction of travel of the rotary tiller. In attempting to direct the path of movement of the rotary tiller the user has only the two rearward handles to rely on. It is by user application of sheer force to the handles that the substantial weight of the rotary is directed to the right or to the left. In the application of this sideways force to the handles downward pressure may be placed on the handles serving to push the depth stake in further to the ground thus increasing the difficulty of redirecting the path of the rotary tiller.